5b Evolution evidence

What are homologous structures?

• A type of structure within living organisms that dates back to the first cell

• A physical feature present among different species that evolved from a common ancestor

• A common ancestor between two different species that are distantly related

• A physical structure absent within species that are all related by the same common ancestor

How does the similar structure of arm bones among humans, birds, whales, and cats prove evolution?

• All of these species independently evolved the same arm bones by chance

• Cats evolved first, whales second, birds third and humans most recently

• Humans, birds, whales and cats are not related in any way

• These species all originated from an ancestor with the same bone structure

1. How do vestigial traits support evolution?

• 1. Vestigial traits originate from genes that are less fit and only found in the fossil record

• 1. These traits do not support evolution and are a current topic of research

• 1. They are a structure from an ancestor that lost function over the course of evolution

• 1. They are a structure found within different species that are related by selection pressures

What is a structure and type of evolution that did not develop from an ancestor but evolved independently among different species due to similar selection pressures?

• Homologous structure

• Convergent evolution

• Divergent evolution

• Analogous structure

The fact that all life uses the same cells, DNA, genes, gene expression and macromolecules indicates that all life originated from the same ancestor. Is this statement:

• True

• False

1. What are homologous genes?

• 1. A type of gene that has recently evolved and does not appear in any other species

• 1. Genes that are most likely to mutate and provide an evolutionary benefit to the species

• 1. A gene that originated in an ancestor that evolved into different species that still have the same gene

• 1. Genes from an ancestor that are found within existing species but no longer serve any purpose

1. If a gene for the hemoglobin protein in blood is found among whales, bats and pigs what assumption can be made about their evolution?

• 1. These species all developed a similar gene due to similar selection pressures

• 1. There can be no assumptions made because we are unable to sample the gene that existed in an extinct species

• 1. These species all share an ancestor that used the same blood protein

• We can assume that this gene may appear similar but has a different function for each species that has it

If a gene for the adrenaline protein is found to be 87% similar between dogs and cats yet 67% similar to hamsters, what evolutionary relationships can be determined?

• Dogs and cats are more closely related than hamsters but all three evolved from an ancestor that had that gene

• Cats, dogs and hamsters all have the same relatedness due to the existence of the same gene

• There is not enough information to make any assumptions on the evolution between these species

• Hamsters and dogs are more closely related than cats but all three evolved from a different ancestor

How does biogeography support evolution?

• Biogeography demonstrates that genes are able to travel across great distances

• Evolution and biogeography are two separate fields of science that are completely unrelated

• 1. The distribution of animals across the planet matches geological changes

• Biogeography is only about the study of geographical distribution of living things and does not relate to evolution

What is the primary reason large flightless birds such as ostriches and emus are only found in the southern continents?

• They evolved from marine animals.

• They are unable to survive in northern climates.

• They lost their ability to fly as the continents separated.

• They were artificially introduced by humans.