Lemurs, monkeys, apes, and humans all belong to the primate family, which
has been the subject of the most thorough genomic study to date. This study
also clarified the time frame in which our evolutionary lineage diverged
from our closest relatives, chimpanzees and bonobos.
Nearly half of the species of primates that are currently alive have had
their genomes sequenced and analyzed by researchers, who reported their
findings on Thursday. Surprisingly, they found that the majority of these
species have higher genetic diversity than humans. Genetic diversity is the
variation within a species that is necessary for adaptation to changing
environments and other challenges.
The researchers identified genetic changes that were specifically human and
involved brain function and development, despite several genetic differences
that were previously believed to be unique to humanity being discovered in
other monkey species. Additionally, they trained an AI model to detect
disease-causing genetic alterations in humans using the genomes of
primates.
The lead author of the main research paper that was published in the
journal
Science, genomicist Lukas Kuderna of the Barcelona Biomedical Research Park's
Institute of Evolutionary Biology in Spain and Illumina Inc (ILMN.O), stated
that studying primate genomic diversity is not only important in light of
the ongoing biodiversity crisis but also has enormous potential to improve
our understanding of human diseases.
Lemurs, lorises, tarsiers, Old and New World monkeys, the "small apes"
(gibbons and siamangs), and the "great apes" (orangutans, gorillas,
chimpanzees, and bonobos) are among the more than 500 species of primates.
The primates with the least resemblance to humans are lemurs and
lorises.
We humans are members of the complex order of animals known as primates,
which includes species with opposable thumbs in the majority of cases,
enormous brains, high levels of dexterity, and good vision. They live
throughout Asia, Africa, especially Madagascar, and the Americas, according
to Kuderna.
The closest living species to us genetically are chimpanzees and bonobos,
who have 98.8% of our DNA in common.
The study revised the timing for the split between the evolutionary
branches that gave rise to humans and those that produced chimpanzees and
bonobos, discovering that this historical event took place 6.9 million to 9
million years earlier than previously thought.
Through a series of species, the human lineage eventually accumulated
important traits including bipedalism, longer limbs, and a bigger brain.
About 300,000 years ago, in Africa, our species, Homo sapiens, first
appeared.
The research looked at the common ancestry of primates. After the asteroid
strike that wiped out the dinosaurs 66 million years ago and allowed mammals
to take control, the last common ancestor of all living primates lived
between 63.3 million and 58.3 million years ago. During this time, amazing
evolutionary innovation occurred.
approximately 60% of monkey species are now threatened with extinction by
human-related stressors such habitat degradation, climate change, and
hunting, and approximately 75% have diminishing numbers.
According to genomicist and research co-author Jeffrey Rogers of the Baylor
College of Medicine in Texas, "the vast majority of primate species have
significantly more genetic variation per individual than do humans." This
demonstrates that the number and type of large population bottlenecks that
affected ancient human populations' genetic diversity were probably
many.
The primate species that require the most urgent conservation efforts may
be determined using the genomic data.
Some of the most threatened primates were the subject of the investigation.
These included the Northern Sportive Lemur, with just about 40 living in the
wild in a limited region of northern Madagascar, and the Western Black
Crested Gibbon, with an estimated 1,500 remaining in the wild dispersed
between China, Laos, and Vietnam.
Kuderna noted that, "interestingly, we find genetic diversity to be a poor
predictor of overall extinction risk." It's possible that this is happening
because the genetic makeup of different species of primate populations
hasn't had time to catch up with and reflect the rapid reduction in
population size.
