It is believed that all organisms are descended from a common ancestor. Evidence of this includes morphological similarities, vestigial characteristics, and observations made within the fossil record. Recently, phylogenetic trees and cladograms are made using DNA sequence analysis to determine the similarity in the genomes of organisms. 

When parts of an animal serve different functions but have similar placement and bone structure (such as a wolf forearm and a whale flipper) and are derived from a common ancestor, these two structures are homologous. Convergent evolution is a process during which two non-related organisms develop analogous structures that serve the same function but have different structures. The bottleneck effect refers to the decrease in genetic diversity that occurs when a population goes through sudden decline and then expands again. Mendel's laws of inheritance refer to the rules by which different traits, or alleles, are passed on from one generation to the next as discrete units of inheritance called genes.

By definition, vestigial structures are structures that are thought to have had a biological function a long time ago but have since lost that function due to evolutionary changes. The human appendix is considered to be an example of a vestigial structure.

Homologous structures show the existence of a shared ancestry through the observation of structural similarities between different species; however, while a human's hand and a cat's paw are structurally similar, they have very different functions.

When a mutation in a gene prevents it from being read, it may be advantageous if the compound produced by the encoded enzyme can be readily obtained from outside sources, saving energy needed to produce the compound on one's own.

A well-known example of this is the GLO gene for vitamin C production. In fruit-eating animals like bats, guinea pigs, and humans, the gene is still present but has a broken promoter, rendering it nonfunctional.

An atavistic trait is a rare appearance of an ancestral structure in an evolved organism. Since dolphins evolved from four-legged mammals, a dolphin born with a pair of hind flippers shows is an atavism, an evolutionary throwback.

Ear wiggling is a an example of a vestigial trait. A rhino's horn in relation to a ram's horn represents an analogous vs. homologous structure. Facial recognition in crows is believed to be a product of coevolution.

Before any truly accurate scientific work on evolution and inheritance could be done, the academic community had to accept the notion that the Earth and its species change over time. If species were fixed, then genetic variation, natural selection, and evolution could not be plausible. Once the scientific community acknowledged the changes in organisms, they were able to proceed into studies to determine why and how such changes occur.

Darwin's finches were distinct from one another due to the size and shape of their beaks. Darwin noted that these distinct beaks allowed the different birds to eat specific food groups. The varying food groups allowed the animals to coexist in the same habitat, without resorting to competing for natural food resources. Each species had evolved to occupy a unique ecological niche in order to survive with minimal competition for resources.

Evolution is a theory that accounts for the changing and transformation of organisms throughout history. For evolution to take place, mutations must occur and change the genetic identity of a population. Essentially, evolution is evidenced by changes in genetic diversity and allele frequency. Each of the answer choices contributes towards the theory of evolution.

Natural selection was coined by Darwin, whose work helped with the theory, and describes the tendency for traits that aid in survival to become more prevalent in a population. Vestigial structures are organs in modern organisms that serve no purpose in increasing biological fitness, but may have been useful to ancestral species in history. Common ancestor organisms are different species that share genetic information with modern species, suggesting that genetic changes in the historic species may have produced the modern species. The fossil record provides genetic material and physical evidence of historic species to use for comparison with modern organisms.

All of these are true. There is lots of evidence supporting the endosymbiotic theory. The mitochondrial genes, in addition to the genes in the nucleus, are also needed to make a functional mitochondrion. These genes are contained in a singular circular chromosome, the same way bacterial genes are organized. Also, when translating their mRNA, they use the same ribosome structure as prokaryotes (70s). The mitochondria are not replicated the same way as other organelles or structures; they undergo binary fission.