Question

The last common ancestor for African apes and hominids a. has been found, and it resembles a gibbon. b. has not yet been identified, but it is expected to be dated from about \(6-7\) MYA. c. has been found, and it has been dated at 30 mya. d. is not expected to be found because there was no such common ancestor. e. most likely lived in Asia, not Africa.

Short answer

The most plausible answer is option b, which states that the last common ancestor for African apes and hominids has not yet been identified, but it is expected to be dated from about 6-7 million years ago. This aligns well with accepted theories in anthropology and fossil evidence.

Step-by-step solution

Understanding the Terminology

The first step in solving this problem is to understand the terminology used in the question and choices. 'African apes' include species like gorillas, chimpanzees, and bonobos. 'Hominids' include humans and our direct and indirect ancestors.

Analyzing Each Choice

Next, each choice should be considered: a. This option suggests that the common ancestor has been found and it resembles a gibbon. However, as per the widely accepted theory, the common ancestor resembled more to a chimpanzee rather than a gibbon. Thus, this option can be ruled out. b. This selection says that the common ancestor hasn't been identified, but is expected to be from about 6-7 million years ago (MYA). This aligns well with the accepted theories in anthropology and is likely the best answer. c. The third option indicates that the common ancestor has been found and dates to 30 million years ago. However, this is much older than most estimates, which place the divergence of hominids and African apes at around 5-10 million years ago. So, this is likely incorrect. d. This choice asserts there was no common ancestor. This conflicts with the widely accepted theory of evolution, which states all species have common ancestors if traced back far enough, so this option is likely not correct. e. This says the common ancestor lived in Asia, not Africa. However, as per fossil evidence, the cradle of humankind is considered to be Africa, and not Asia. This suggests that this option might also not be correct.

Making a Conclusion

After analyzing each choice, it seems safe to conclude that option b is the most plausible. This decision is based on accepted scientific theories and fossil evidence that suggest the last common ancestor of African apes and hominids has not yet been identified, but is believed to have lived around 6-7 million years ago.

Key concepts

Human Evolution

At the heart of biological anthropology lies the fascinating journey of human evolution, a tale woven through millions of years of genetic and environmental interplay. From our most ancient forebears to the advent of Homo sapiens, this story illuminates the transformative path that has led to the modern human.

Originating from a last common ancestor shared with today's African apes, comprising species such as gorillas and chimpanzees, our evolutionary saga began in the lush landscapes of Africa. According to prevailing scientific understanding, this last common ancestor likely existed approximately 6 to 7 million years ago (MYA). This timeline is deduced from a meticulous combination of fossil records, comparative anatomy, and genetic data.

Despite the allure of the 'missing link', a term popularized in early anthropological studies, contemporary science recognizes that evolution is not a linear process but a complex tree with many offshoots. Some of these branches led to now-extinct hominids, while others continued towards the emergence of our own species, Homo sapiens. It's critical to convey that as paleontologists and anthropologists uncover new fossils, our understanding of this evolutionary journey continues to evolve, much like the species themselves.

African Apes Phylogeny

The phylogenetic tree, which showcases the evolutionary relationships among species, reveals that the African apes and hominids diverged from a shared lineage. The phylogeny of African apes is a complex, branching story that encompasses several species, including gorillas, chimpanzees, and bonobos, with hominids forming a closely related yet distinct lineage.

Many students might find the intricate web of ancestral ties confusing, but it's essential to simplify the African apes phylogeny by highlighting the key milestones and evolutionary markers. The genetic and morphological similarities among these primates bolster the hypothesis that they share a relatively recent last common ancestor, contrary to the much older 30 million year mark suggested by some options in the exercise.

A clearer understanding of this phylogeny emerges from fossil discoveries and advanced DNA analysis. Visualising phylogenetic trees and understanding the concept of adaptive radiation—a process where organisms diversify rapidly into a multitude of new forms—can help to illuminate the shared past and subsequent divergence of African apes and hominids. This understanding also clarifies why, despite some similarities to Asian apes like gibbons, the last common ancestor would most closely align with the African apes' characteristics.

Anthropology

Anthropology, the holistic study of humanity's past and present, fuses various disciplines to construct a comprehensive picture of human history, culture, biology, and social interactions. Its biological or physical subfield is especially pertinent when discussing the last common ancestor of hominids and African apes.

Within this realm, anthropologists employ methods ranging from archaeological digs uncovering ancient artifacts to the analysis of skeletal remains, which provide a wealth of information about our progenitors. The tools of molecular anthropology, involving the scrutiny of DNA sequences, also play an invaluable role in tracing the genetic links that weave through our evolutionary tapestry.

Modern anthropology espouses the view that evolutionary and fossil records substantiate the emergence of hominids in Africa, where the wealth of evidence supports the continent's role as the 'cradle of humankind'. It's through the anthropological lens that students can appreciate the interdisciplinary efforts that lead to illuminating discoveries about our shared ancestry with African apes, insights that are continually refined with each new finding.