Evolution Exam 4
Which of these statements about vertebrates limb formation are correct?
- A cell in a vertebrate limb bud "knows" where it is through the relative concentration it experiences of certain proteins that, in turn, are only secreted from certain cells in certain areas of the limb bud. - The Sonic hedgehog genes, the FGF-4 and 8 genes, and the Wnt7a gene establish the axes of the limbs. These genes are not part of the Hox gene family, but they influence Hox gene expression. - Hox genes that originally evolved in the context of specifying the anterior-posterior body axis have been co-opted to coordinate the growth of complex limbs.
Zhongwei Lin and colleagues (2012) uncovered the genetic basis for the non-shattering phenotype in sorghum. Darwin would have been pleased with this research because the study combined two areas that were fundamentally important to his understanding of evolution and the evidence for it. What are these two areas?
- artificial selection in domesticated plants - developmental biology
Which of these traits are synapomorphies of all apes as compared to Old World monkeys (baboons, macaques, etc.)? - color vision - more flexible hips, ankles, and wrists - opposable thumbs - no tail - relatively larger brain (compared to body size)
- more flexible hips, ankles, and wrists - no tail - relatively larger brain (compared to body size)
Match the terms: 1. The clade of Old World primates that have a relatively large brain and no tail. 2. The clase that includes humans and old world monkeys, but not new world monkeys. 3. The clade that includes orangutans and humans, but not gibbons. 4. The clade that includes homo and Australopithecus, but not chimpanzees. 5. The hypothesis that modern humans evolved recently in Africa, and spread to other continents within the last 200,000 years without interbreeding. 6. A phylogeny of all the alleles of a certain gene.
1. Apes 2. Catarrhini 3. Great apes 4. Hominins (also hominids-this is the older term) 5. Out-of-Africa or African replacement model 6. Gene tree
Match the term: 1. Homology in structure that is due to underlying homology in the genes that affect the development of the structure. 2. Usage of a pre-existing gene to function in development of a novel characteristic that was not its original purpose. 3. A class of genes involved in signaling to cells during development where they are in the body, and that share a particular 180-base pair DNA-binding motif. 4. Expression of a series of linked genes in a sequence along locations in the animal, or in a sequence in time, that matches their physical sequence on the chromosome. 5. A technique of determining when and where certain genes are expressed, based on addition of fluorescent DNA that will bind to mRNA made by those genes.
1. Deep homology 2. Re-purposing, co-opting, or exaptation 3. Homeobox genes 4. Colinearity 5. In situ hybridization
Give the name of the hominin genus described by each phase. 1. Known from a single crushed, distorted skull that is 6-7 million years old. 2. Known from a single crushed, distorted skull that is 3.5 million years old, and that has an unusually flat face for its age. 3. Bipedal; very large brain case; flat face; small teeth; almost always associated with tools. 4. Bipedal; relatively small braincase; projecting face with small teeth; small in stature. 5. Bipedal; relatively small braincase; very large face with enormous cheek teeth and massive jaws.
1. Sahelanthropus 2. Kenyanthropus 3. Homo 4. Australopithecus 5. Paranthropus
In which of the following do aldehyde dehydrogenase catalyze the oxidation of aldehydes? 1. Archaea 2. Eukaryotes 3. Bacteria 4. All of the above
4. All of the above
Evidence that homeotic loci in vertebrates are homologous to those in invertebrates includes: 1. Similarities in DNA sequence 2. Similarities in how the genes are organized on the chromosome. 3. The fact that they descended from a common ancestor. 4. The first and second choices are both evidence that these loci are homologous.
4. The first and second choices are both evidence that these loci are homologous.
Although attempts to date the divergence between humans and chimps using molecular sequence data do not perfectly agree, a rough consensus from multiple analyses would place the divergence date at _________.
5 to 7 million years ago.
Which genus or genera of hominin is/are most consistently associated with stone tools?
A. Homo
The accompanying figure shows the percentage of pairwise genetic comparisons within sample populations of living hominids, graphed against the percentage of sequence divergence for each pair. We can conclude from the figure that ___________.
Any randomly selected pair of humans in the world should differ in their mitochondrial DNA sequences by less than 6%.
Which piece of evidence BEST supports the "multiregional evolution" model of the evolution of modern humans?
Both Asian fossil Homo erectus and modern Asian human populations show a high frequency of shovel-shaped incisors.
Chimpanzees and gorillas share the trait of knuckle-walking, which humans do not generally have. Why do most scientists NOT classify chimpanzees and gorillas as each other's closest relatives? A. The majority of genetic evidence places chimps closest to humans, not to gorillas. B. Fossil evidence suggests that knuckle-walking was present in ape ancestors and is not a uniquely derived trait for chimps and gorillas. C. Chimps and humans share more unique features in common than either share with gorillas. D. Fossil apes that are thought to be closest to humans show adaptations for knuckle-walking, implying that humans have secondarily lost the trait. E. All of the above
E. All of the above
T/F: Genes in different species derived from a common ancestor's gene are said to be paralogous.
F
Which of the following are trends in primate evolution that define the lineage leading to humans? A. Enhanced daytime vision B. Upright walking C. Power grip and precision grip D. Teeth for all occasions E. Brains, behavior, and culture F. All of these.
F. All of these.
Stephen Jay Gould drew on the discoveries of gene regulation to suggest that much of evolutionary change could be attributed to alterations in the relative timing of developmental events. This was known as ________, another example of modest changes in gene regulation leading to dramatic morphological change.
Heterochrony
Which of the following statements is true?
Humans probably did descend from a knuckle-walking ancestor.
The fossil Sahelanthropus tchadensis from the Djurab Desert of Chad, dated at 6 to 7 million years ago, may be a hominin (i.e. share more recent common ancestry with humans than with any other ape because of ____________.
It's relatively flat face.
The accompanying figure shows that humans have thicker thumb metacarpals than chimps and bonobos, with broader heads. This is directly correlated with humans __________.
More elaborate thumb musculature and better precision grip.
All non-African humans today show evidence of a limited amount of past interbreeding with _________.
Neanderthals
Judging by the nature of modern humans, chimpanzees, and bonobos, which of these traits did the last common ancestor of all three probably NOT show?
Strictly heterosexual mating patterns.
T/F: Humans and chimpanzees are 99% similar genetically.
T
Modern humans have lost the system of air sacs that other great apes have. Whatever the reason for this loss, one resulting effect on human behavior was ___________.
The ability to pronounce sounds more clearly.
During development, home prices loci specify:
The location of cells in time and space.
The evidence from Panganiban et al's studies that appendage-like outgrowths of the body wall are homologous in all bilaterally symmetric animals is particularly strong because:
The same pattern of DII expression was found in a wide range of distantly related taxa.
Vincent Sarich and Allan Wilson estimated that humans diverged from their closest living primate relatives about 5 million years ago. What line of evidence did they use initially?
reactions between primate serum proteins and antibodies to human serum
