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1.
Jean E. Turnquist Daniel Schmitt Michael D. Rose John G.H. Cant 《American journal of primatology》1999,48(4):263-281
Pendular motion during brachiation of captive Lagothrix lagothricha lugens and Ateles fusciceps robustus was analyzed to demonstrate similarities, and differences, between these two closely related large bodied atelines. This is the first captive study of the kinematics of brachiation in Lagothrix. Videorecordings of one adult male of each species were made in a specially designed cage constructed at the DuMond Conservancy/Monkey Jungle, Miami, FL. Java software (Jandel Scientific Inc., San Rafael, CA) was used for frame‐by‐frame kinematic analysis of individual strides/steps. Results demonstrate that the sequence of hand and tail contacts differ significantly between the two species with Lagothrix using a new tail hold with every hand hold, while Ateles generally utilizes a new tail hold with only every other hand hold. Stride length and stride frequency, even after adjusting for limb length, also differ significantly between the two species. Lagothrix brachiation utilizes short, choppy strides with quick hand holds, while Ateles uses long, fluid strides with longer hand holds. During brachiation not only is Lagothrix's body significantly less horizontal than that of Ateles but also, within Ateles, there are significant differences between steps depending on tail use. Because of the unique nature of tail use in Ateles, many aspects of body positioning in Lagothrix more closely resemble Ateles steps without a simultaneous tail hold rather than those with one. Overall pendulum length in Lagothrix is shorter than in Ateles. Tail use in Ateles has a significant effect on maximum pendulum length during a step. Although neither species achieves the extreme pendulum effect and long period of free‐flight of hylobatids in fast ricochetal brachiation, in captivity both consistently demonstrate effective brachiation with brief periods of free‐flight and pendular motion. Morphological similarities between ateline brachiators and hylobatids are fewer and less pronounced in Lagothrix than in Ateles. This study demonstrates that Lagothrix brachiation is also less hylobatid‐like than that of Ateles. Am. J. Primatol. 48:263–281, 1999. © 1999 Wiley‐Liss, Inc. 相似文献
2.
For species of primates in which females emigrate, we would expect males within groups to be related to one another. Kin selection
theory suggests that these males should associate preferentially with one another, be more affiliative and cooperative with
one another than females are, and compete less overtly with one another over reproductive opportunities than males in female
philopatric taxa do. Precisely these patterns of social behavior characterize well-studied populations of 2 of the 3 atelin
primate genera: spider monkeys (Ateles) and muriquis (Brachyteles). For the third atelin genus, Lagothrix, patterns of intragroup social behavior have been less well-documented. We studied the social and reproductive behavior of
lowland woolly monkeys (Lagothrix lagotricha poeppigii) in Ecuador during a one-year observational study and subsequently used molecular techniques to investigate population genetic
structure and dispersal patterns for this taxon.
Among adult male woolly monkeys, both affiliative and agonistic interactions were rare, and males were seldom in close proximity
to one another. Relationships among male woolly monkeys are best characterized as tolerant, especially in the context of mating
wherein direct competition among males was minimal despite the fact that females mated with multiple males. Relationships
among females were likewise generally tolerant but nonaffiliative, though females often directed harassment towards copulating
pairs. Affiliative interactions that did occur among woolly monkeys tended to be directed either between the sexes—primarily
from female to male—or from younger towards older males, and the proximity partners of females tended to be members of the
opposite sex. These results suggest that bonds between the sexes may be more important than same-sex social relationships
and that direct female-female competition is an important feature of woolly monkey reproductive biology. Our genetic results
indicate that, as in other atelins, dispersal by females is common, but some male dispersal likely occurs as well. In some
but not all groups we studied, nonjuvenile males within social groups were more closely related to one another on average
than females were, which is consistent with greater male than female philopatry. However, differences in these patterns among
our study groups may reflect local variation in dispersal behavior. 相似文献
3.
Many mammals coincide their reproductive activities with factors such as ambient temperature, rainfall, and food availability. In primates that invest immediate food intake into reproduction, the periods of maximum fruit production often coincide with the peak of lactation (to maximize maternal survival) or the occurrence of weaning (to maximize infant survival). This study investigates the relationship between reproductive periods and the availability of ripe fruit in the habitat of a population of wild squirrel monkeys (Saimiri collinsi) in Amazonian Brazil. We combine data from several years (2002–2003; 2011–2015) during which we followed the monkeys and quantified the occurrence of matings, gestations, births, and the number of lactating females. We also collected rainfall and plant phenological data for 24 months. Our results confirm that reproductive events are highly seasonal in S. collinsi. The period of weaning corresponded to the peak in the abundance of ripe fruits consumed by the monkeys. This indicates that the period of infant nutritional independence is optimally timed to coincide with periods of greater food production in this habitat. We suggest that seasonal breeding in these primates does not necessarily reduce maternal energetic stress, but likely improves infant survivorship. 相似文献
4.
Stacey R. Tecot 《International journal of primatology》2010,31(5):715-735
Highly seasonal breeding has been considered one of the keys to understanding Malagasy primate socioecology. Strict seasonal
breeding may be particularly critical for Malagasy primates because they live in such energetically challenging seasonal environments.
Lemurs also live in highly unpredictable environments, and there is growing evidence that reproductive timing may be mediated
by additional factors, suggesting that more relaxed breeding seasonality is adaptive in some cases. I tested the adaptive
breadth of the birth peak in Eulemur rubriventer, which breed in several different months. I describe reproduction in the species by determining the timing and extent of
the birth season (period in which all births occur) and birth peak (period in which the majority of births occur); test whether
relaxed reproductive seasonality might increase reproductive success by comparing infant mortality within and outside the
birth peak; and model the extent to which fruit availability has an influence on the timing of reproduction. I collected birth
data on 5 groups in 2003–2005, which I combined with demographic data that D. Overdorff collected from 5 focal groups and
additional censused groups between 1988 and 1996. Thirty births occurred in 8 different months. Births were significantly
seasonal, with a unimodal birth peak in late August/September/October, and a mean birth date of October 11. Twenty-three births
(76.7%) occurred within 54 d (14.79%) of the year. No births occurred May–July, indicating that conceptions did not occur
from late December through late February, and cycling (estimated using gestation length) did not occur until ca. 101 d after the austral summer solstice (December 21). Of 22 infants followed regularly, 18 were born in the birth peak,
of which 2 died (11%). All 4 infants born out of season died. Based on fruit availability, I calculated a Theoretical Overlap
index (T), which indicated a 3-mo window with optimal food conditions for reproduction. This window corresponded to the timing
and breadth of the birth peak in Eulemur rubriventer. These results indicate that a breeding season >3 mo within a given year is not adaptive in the species, likely due in large
part to the availability of fruit during key reproductive stages, particularly before breeding. 相似文献
5.
Carlos A. Peres 《International journal of primatology》1994,15(3):333-372
I studied gray woolly monkeys (Lagothrix lagotricha cana)in an undisturbed central Amazonian terra firme forest, near the headwaters of the Urucu river, Tefé, Amazonas, Brazil (5°50’S,
65°16’W). I report the diet and feeding ecology of a group of 39–41 individuals, based on systematic feeding observations
obtained during 11 months. Woolly monkeys are primarily frugivorous; mature fruits and young seeds account for 83 and 7% of
3298 feeding records, respectively. On a seasonal basis, however, they relied heavily on young foliage (16%), seed-pod exudates
(6%), and flowers (3%), particularly during the greatest annual period of ripe fruit scarcity, as determined by a phenological
survey. Animals represent only 0.1% of their year-round diet, and they spent little time capturing arthropods and other prey
items. Although at least 225 plant species, belonging to 116 genera and 48 families, are in their diet, the three top-ranking
families (Moraceae, Sapotaceae, and Leguminosae) account for 43% of their food species and 63% of the time they spent feeding
on a year-round basis. I compare the feeding ecology and diet of L. 1. canain the Urucu and other taxa of Lagothrixin upper Amazonia — the last large-bodied Neotropical primates to be studied — to those of other ateline genera: Atelesand Brachyteles.
An erratum to this article is available at . 相似文献
6.
Glenn C. Conroy 《American journal of physical anthropology》1982,57(1):7-12
A discriminant analysis was performed on 226 ceboid skulls using data on emissary foramina size and shape. The purposes of the study are to 1) measure the success with which these discriminating variables can distinguish among platyrrhine genera and 2) derive a set of classification functions which will permit the classification of new cases with unknown group membership (i.e., fossil skulls). This technique is able to correctly classify 80% of the 226 ceboid skulls. Support is given to the allocation of Chiropotes, Cacajao, and Pithecia into one morphologically unified subfamily, Pitheciinae. Alouatta, Ateles, and Lagothrix also share many similarities in emissary foramina size and shape and their inclusion into one subfamily, Atelinae, is probably warranted. The distinctiveness of Cebus in these same morphological features is apparent. Possibilities for extending this procedure to study fossil lineages in platyrrhines are discussed. 相似文献
7.
The ateline monkeys constitute as certain a monophyletic group as there is among primates. The group is intriguing because
while their adaptations are well-documented and their monophyly as a group is unquestioned, their phylogenetic interrelationships
are controversial. Molecular data indicate a phylogeny at odds with their morphology. Traditional morphological comparisons
isolate Alouatta from the atelins, and link Ateles and Brachyteles as a sister group to the exclusion of Lagothrix. In contrast, several recent molecular studies point to a closer relationship between Brachyteles and Lagothrix than between Brachyteles and Ateles. At the heart of the problem lie the assumptions we make about the validity of data and the homology of observed traits.
The fossil record further confounds the issue. We must account for the fossil record because it is positive evidence. But
we cannot control how much of it there is or how much of it ever will be known. At this point in time, the ateline molecular
and fossil record provoke us to examine critically our morphological approach to phylogenetic modeling. 相似文献
8.
The income-capital breeding model was developed to explain birth seasonality and reproductive strategies in female animals
in relation to the abundance of food energy in the environment. An income breeder uses currently available energy and acts
so as to maximize either maternal survival or weanling survival, depending on the relationship between timing of births and
abundance of food energy. A capital breeder stores energy reserves for future reproductive use. Here we examined energetic
influences on reproductive seasonality in a population of female white-faced capuchins (Cebus capucinus) living in a seasonal dry forest in Costa Rica. Our objectives were to determine: 1) the degree of fruiting seasonality in
capuchin food trees and 2) the temporal relationship between capuchin births/conceptions and fruit abundance. Our sample included
25 yr of birth data (N = 100 births), 4 yr of capuchin fruit tree phenology data, and 18 mo of ovarian hormone data, which we used to calculate
gestation lengths and estimate conception dates. Using circular statistics, we found that the mean peak in fruit abundance
occurs in June, and that this population of capuchins reproduces seasonally, with 44% of births occurring within a 3-mo period
(May to July, mean month = May). We propose that white-faced capuchins can be generally classified as income breeders that
maximize maternal survival instead of weanling survival and that they time infant births such that the most energy expensive
period of reproduction, mid-to-late lactation, occurs during the mean peak in fruit abundance. 相似文献
9.
Given appropriate ecological and social conditions, natural selection should favor individuals that can concentrate their reproductive events to a particular time of the year that offers high opportunities for infant survivorship. Previous studies on births in Alouatta caraya in Northern Argentina revealed the existence of a peak during the dry season—a period with scarcity of food resources—in mainland gallery forest (G. E. Zunino, Extra 133: 1–10, 1996). The time of conception and the period of independence of the offspring are positively correlated with precipitation, temperature and availability of food. Offspring became independent from their mothers when the availability of resources was high, and conception coincided with the peak of fruit production. Our goal was to examine patterns of birth seasonality in Alouatta caraya in flooded forest on an island in Northern Argentina for comparison with the mainland population. Both sites are at similar latitudes, but differ in forest type. The results indicate that the availability of new and mature leaves is more consistent throughout the year in the flooded forest (p<0.05); however, there was no difference in the availability of fleshy fruits between sites (p>0.05). The pattern of births differed between the gallery forest and the flooded forest (2-way Anova, p<0.001). In the flooded forest births occurred throughout the year, which supports the contentions that howlers do not have a fixed birth season and that the observed variation in the timing of births appears to represent a facultative behavioral response to changes in food availability. 相似文献
10.
Irwin S. Bernstein Peter Balcaen Lawrence Dresdale Harold Gouzoules Michael Kavanagh Thomas Patterson Patricia Neyman-Warner 《Primates; journal of primatology》1976,17(3):401-411
A population survey of nonhuman primates in an area of northern Colombia was conducted using repeated systematic census techniques
as well as exploratory transects. Both remnant forest patches and more extensive forests were examined for comparison. WhereasLagothrix andAteles were most numerous in extensive forests,Lagothrix was virtually absent in remnant forests.Cebus, Alouatta andSaguinus persist in remnant forests, and the last may even find second growth a favorable habitat. These results are in good agreement
with independent studies in a second area in the South. 相似文献
11.
The two subspecies of the black spider monkey, Ateles paniscus paniscus and A. p. chamek, can be distinguished by their chromosome number, 2n = 32 in the former and 2n = 34 in the latter. This difference most probably is the result of a tandem fusion between chromosomes 4 and 13 of the original Ateles karyotype (2n = 34) to form a unique metacentric chromosome in A. p. paniscus. Further differences between the subspecies concern the presence of additional interstial or terminal C-bands in chromosomes 3, 5, and 12 of A. p. paniscus. A third difference is that chromosome 12 is metacentric in A. p. paniscus but is submetacentric in A. p. chamek. A. p. chamek shows dimorphisms caused by pericentric inversions in pairs 1, 5, 6, and 7 as well as in the Y chromosome. Since the dimorphisms in pairs 5 and 7 are only found in homozygous condition, they may indicate the existence of geographic variation within this subspecies. Differences in external characteristics possibly reflect these chromosomal difference. The necessity to lend A. p. paniscus full specific status should be considered, since karyologically this is the most distinct one of all forms of Ateles. In captive breeding A. p. paniscus should evidently be treated as a separate population, as hybridization with A. p. chamek may result in offspring with reduced fertility. The intra-subspecific karyological variation in A. p. chamek and its possible consequences for taxonomy and captive breeding require further investigation. 相似文献
12.
Christopher P. Kofron 《Acta zoologica》2008,89(1):53-58
The long‐tongued nectar bat Macroglossus minimus lagochilus (Megachiroptera, Pteropodidae) is a small fruit bat inhabiting South‐east Asia. Its reproduction was studied in Brunei, Borneo, where individuals were usually captured in rainforest (Ulu Temburong). Adult females (n = 23) had body masses of 13.0–19.0 g, with forelimbs 3.83–4.33 cm in length. All adult females were pregnant, with pregnancies observed during every month except May, September and November when no adult females were captured. Female M. minimus in Brunei have a reproductive cycle that is consistent with a pattern of seasonal bimodal polyoestry. Most births appear to occur from November to May, during which time females experience two births: the first centred around November and December, and the second centred around April and May. These two birth seasons appear correlated to the two seasons of greater rainfall in Brunei: October to December, and April to July. Oestrous and mating apparently occur soon after each birth; however, there appears to be a 2‐ to 3‐month period of delayed embryonic development following the births centred around April and May. The data are consistent with embryonic development commencing around July and August (after a delay) for the births centred around November and December, and around December and January for the births centred around April and May. The data suggest that all adult females participate in each breeding season. Adult males (n = 20) had body masses of 12.5–18.0 g, with forelimbs 3.91–4.26 cm in length. 相似文献
13.
The taxonomic relationships among the four genera of the Atelidae family, Alouatta (Howler), Ateles (Spider), Lagothrix (Woolly) and Brachyteles (Muriqui), have been the subject of great debate. In general, almost all authors agree with the assignment of Howler monkeys
as the basal genus, either in its own tribe Alouattini or in the subfamily Alouattinae, but they disagree on the associations
among the other members of the family. Muriquis have been grouped with Spider monkeys based on the fact that they share various
behavioral and morphological characteristics. Cladistic analyses using morphological, biochemical, karyotype and behavioral
characteristics depicted a phylogenetic tree that places Howler as the basal genus and the remaining genera in an unresolved
politomy. More recent studies using molecular data have suggested that Muriqui and Woolly monkeys are sister groups. However,
a recent study based on nuclear and mtDNA argued that politomy is what best represents the relationships among Spider, Woolly
and Muriqui. To contribute to this debate we have added new data from two nuclear genes, Transferrin and von Willebrand Factor,
and using an alignment of 17,997 bp we demonstrate that a total analysis strongly supports the Muriqui-Woolly clade. A gene-to-gene
approach showed that four of the eight nuclear genes provide support for the Muriqui-Woolly clade, two strongly and two moderately,
while none of the eight genes provide support for any alternative arrangement. The mitochondrial genes were not able to resolve
the politomy. A possible reason for the difficulty in resolving atelid relationships may be the short period of time separating
each cladogenetic event in the evolutionary process that shaped this family. 相似文献
14.
Katharine Milton 《Primates; journal of primatology》1981,22(4):574-579
Six and a half years of data collected on the reproductive parameters of a population of free-rangingAteles geoffroyi show the following characteristics: seasonality of births; interbirth interval of ca. 32 months; nursing by infants for more
than 2 years; and reproductive life span of females continuing beyond 20 years of age. These characteristics appear to reflect
adaptations to a primary resource base, ripe fruit, that is very low in protein and patchily distributed in space and time
in tropical forests. 相似文献
15.
We assessed the role of visual and olfactory cues on oviposition preference in the oligophagous tomato fruit fly, Neoceratitis cyanescens (Bezzi) (Diptera: Tephritidae). In a field survey, we evaluated the stage of susceptibility of field‐grown tomatoes by monitoring N. cyanescens infestations from fruit‐setting up to harvest, in relation to post‐flowering time, size, and visual properties of fruit. In two‐choice laboratory experiments, we tested the degree to which females use visual and olfactory cues to select their host plant for oviposition. In addition, we investigated the ability of flies to avoid fruit already infested by conspecific eggs or larvae, and the influence of natal host fruit on oviposition preference. Neoceratitis cyanescens females preferentially lay their eggs in small yellow‐green unripe fruit (2–3.5 cm diameter, 10–21 days post‐flowering). Damage to fruit was significantly affected by brightness and size properties. In laboratory experiments, females chose to lay their eggs in bright orange rather than yellow domes. On the sole basis of olfactory stimuli, females showed a significant preference for unripe vs. ripe host fruit, for unripe fruit vs. flowers or leaves, and for host vs. non‐host fruit (or control). However, colour interacted with odour as females dispatched their eggs equally between the yellow dome and the bright orange dome when unripe fruit of tomato was placed under the yellow dome vs. ripe fruit under the bright orange dome. When offered real ripe and unripe tomatoes, females preferred unripe tomatoes. Females significantly chose to lay eggs in non‐infested fruit when they were given the choice between these or fruit infested with larvae. In contrast, recent stings containing eggs did not deter females from laying eggs. Rather, they could have an attractive effect when deposited within <1 h. Regardless of their natal host plant, tomato or bugweed, N. cyanescens females laid significantly more eggs in a dome containing bugweed fruit. However, 15% of females originating from tomato laid eggs exclusively in the dome with tomato, against 3% of females originating from bugweed. 相似文献
16.
Robin S. Waples Tiago Antao 《Evolution; international journal of organic evolution》2014,68(6):1722-1734
In iteroparous species, it is easier to estimate Nb (effective number of breeders in one reproductive cycle) than Ne (effective population size per generation). Nb can be used as a proxy for Ne and also can provide crucial insights into eco‐evolutionary processes that occur during reproduction. We used analytical and numerical methods to evaluate effects of intermittent breeding and litter/clutch size on inbreeding Nb and Ne. Fixed or random litter sizes ≥ 3 have little effect on either effective‐size parameter; however, in species (e.g., many large mammals) in which females can produce only one offspring per cycle, female Nb = ∞ and overall Nb = 4Nb(male). Intermittent breeding reduces the pool of female breeders, which reduces both female and overall Nb; reductions are larger in high‐fecundity species with high juvenile mortality and increase when multiple reproductive cycles are skipped. Simulated data for six model species showed that both intermittent breeding and litter‐size constraints increase Ne, but only slightly. We show how to quantitatively account for these effects, which are important to consider when (1) using Nb to estimate Ne, or (2) drawing inferences about male reproductive success based on estimates of female Nb. 相似文献
17.
In Florida, habitats that include the breeding territories of Crested Caracaras (Caracara cheriway) are protected, but non‐breeding individuals may be vulnerable because they may occupy different areas and habitats. We captured and radio‐tagged 58 non‐breeding caracaras in Florida from July 2006–March 2009, determined their locations during weekly flights, and used GIS and compositional analysis to evaluate range sizes and habitat use. Non‐breeding caracaras (N = 58) ranged five times more widely during breeding seasons (N = 573 locations) than during non‐breeding seasons (N = 592 locations), and ranged >250 times more widely than breeding caracaras that defend territories year‐round. The large ranges of non‐breeders suggest they may be searching for and evaluating prospective territories or breeding opportunities (territory prospecting). Pasture occupied by cattle was the most used habitat relative to availability and was used more than pasture without cattle, likely because insects associated with cattle are an important food source for caracaras. Cattle numbers in Florida are declining and, because both breeding and non‐breeding caracaras primarily occupy pasture, this may present difficulties for long‐term management. Citrus groves were also used more than expected given availability by non‐breeding caracaras, but are rarely included in nesting territories. Because pasture and citrus were often adjacent, we suggest that citrus groves may function as refugia from socially dominant breeding caracaras. Conservation and recovery efforts for Florida's caracara population are needed throughout the range of non‐breeders, and should include management that ensures availability of habitat matrices of cattle pasture and citrus groves. 相似文献
18.
Labeo horie Heckel is increasingly becoming commercially important in Lake Chamo but its reproductive biology in the lake is not well enough to guide its management. Sex ratio, breeding season, length at first maturity and fecundity of L. horie were studied from 1197 fish samples collected between August 1998 and October 1999 in Lake Chamo, Ethiopia. The sex ratio was significantly different (χ 2 = 12.12, P < 0.001). The peak‐breeding period was during the rainy months of March to May, during which time more than 90% of both sexes had ripe gonads. The size at maturity ( L m50 ) of males was 52 cm while the L m50 of females was 62 cm. The smallest ripe male in the catch was 46.7 cm and weighed 890 g while the smallest ripe female caught was 49.5 cm and weighed 1145 g. The weight of ripe ovaries ranged from 54.3 g to 991.8 g and contained between 68,400 and 1,320,400 eggs. Relative fecundity ranged between 60 and 290 eggs per g of body weight. The relationships between fecundity and total length and between fecundity and total weight were curvilinear, while the relationship between fecundity and ovary weight was linear. L. horie conformed to the general pattern of reproduction in a tropical environment where peak‐breeding activity occurred during the rainy season. In order to protect the spawning population, fishing pressure should be minimized during breeding time at the shallower littoral regions. 相似文献
19.
The breeding performance of seabirds is constrained by the availability of marine‐based prey, which may be influenced by competition with other seabirds, and environmental conditions. Fairy prion (Pachyptila turtur) populations have declined substantially in New Zealand since the introduction of mammalian predators; remaining small populations provide an opportunity to examine the effect of environmental factors on reproductive success in the absence of competition. Using 11 years of nest monitoring data and eight years of chick measurements we investigated (i) the link between physical environmental factors, breeding success rates and chick fledging size, and (ii) the relationship between chick fledging size and likelihood of natal‐colony recapture. Despite annual variations in the Southern Oscillation Index (SOI) and sea surface temperatures (SST), breeding success and chick fledging weights remained similar throughout the entire period, possibly due to the use of behavioural buffering mechanisms by parents. Fledgling wing lengths differed among years, and were predicted by early winter and early spring values of the SOI and late spring and summer SSTs. In years of high SOI and high SST, fairy prions fledged with longer wings, possibly due to increased availability of the euphausiid Nyctiphanes australis, their main prey. River flows and rainfall were unrelated to breeding success or chick measurements: the influence of freshwater on the marine system at this locality acts at smaller timescales than those studied here. Using the 2004 and 2005 cohorts, there was no link between fledging size and likelihood of recapture, except for the 2005 cohort which had unusually low 6‐year recapture rates, and shorter‐than‐average wing lengths. A combination of low sea temperatures and an El Niño event in 2005 may have led to a reduction in euphausiid availability, ultimately affecting post‐fledging survival. 相似文献
20.
M. A. Medeiros R. M. S. Barros J. C. Pieczarka C. Y. Nagamachi M. Ponsa M. Garcia F. Garcia J. Egozcue 《American journal of primatology》1997,42(3):167-178
The chromosomes of 22 animals of four subspecies of the genus Ateles (A. paniscus paniscus, A. p. chamek, A. belzebuth hybridus, and A. b. marginatus) were compared using G/C banding and NOR (nucleolar organizer region) staining methods. The cytogenetic data of Ateles in the literature were also used to clarify the phylogenetic relationships of the species and subspecies and to infer the routes of radiation and speciation of these taxa. Chromosomes 6 and 7 that showed more informative geographic variation and the apomorphic form 4/12, exclusively in A. p. paniscus, are the keys for understanding the evolution, radiation, and specification of the Ateles taxa. The ancestral populations of the genus originated in the southwestern Amazon Basin (the occurrence area of A. paniscus chamek) and spread in the Amazon Basin and westward, crossing the Andes and colonizing Central America and northwesternmost regions of South America. The evolutionary history of the northern South American taxa is interpreted using the model of biogeographical evolution postulated by Haffer [Science 185:131–137, 1969]. Ateles paniscus paniscus is the genetically most differentiated form and probably derives from A. belzebuth hybridus. Based on the karyotype differences, the populations of Ateles can be divided into four different group. These findings indicate the necessity of a more coherent taxonomic arrangement for the taxa of Ateles. Am. J. Primatol. 42:167–178, 1997. © 1997 Wiley-Liss, Inc. 相似文献