When organisms have similar bone structures What does that indicate about them?

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Table of Contents

When organisms have similar bone structures What does that indicate about them?

skeletons of humans and gorillas compared

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Key People:Georges Cuvier Johannes Müller Alfred Sherwood Romer Franz Weidenreich Louis-Jean-Marie Daubenton...(Show more)Related Topics:anatomy...(Show more)

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comparative anatomy, the comparative study of the body structures of different species of animals in order to understand the adaptive changes they have undergone in the course of evolution from common ancestors.

When organisms have similar bone structures What does that indicate about them?

homologies of vertebrate forelimbs

Modern comparative anatomy dates from the work of French naturalist Pierre Belon, who in 1555 showed that the skeletons of humans and birds are constructed of similar elements arranged in the same way. From this humble beginning, knowledge of comparative anatomy advanced rapidly in the 18th century with the work of two French naturalists—Georges-Louis Leclerc, comte de Buffon, and Louis-Jean-Marie Daubenton—who compared the anatomies of a wide range of animals. In the early 19th century, French zoologist Georges Cuvier placed the field on a more scientific basis by asserting that animals’ structural and functional characteristics result from their interaction with their environment. Cuvier also rejected the 18th-century notion that the members of the animal kingdom are arranged in a single linear series from the simplest up to humans. Instead Cuvier arranged all animals into four large groups (vertebrates, mollusks, articulates, and radiates) according to body plan. Another great figure in the field was the mid-19th-century British anatomist Sir Richard Owen, whose vast knowledge of vertebrate structure did not prevent him from opposing the theory of evolution by natural selection which was developed and made famous by British naturalist Charles Darwin. Darwin made extensive use of comparative anatomy in advancing his theory, and it in turn revolutionized the field by explaining the structural differences between species as arising out of their evolutionary descent by natural selection from a common ancestor.

Since Darwin’s time, the study of comparative anatomy has centred largely on body structures that are homologous—i.e., ones in different species that have the same evolutionary origin regardless of their present-day function. Such structures may look quite different and perform different tasks, but they can still be traced back to a common structure in an animal that was ancestral to both. For example, the forelimbs of humans, birds, crocodiles, bats, dolphins, and rodents have been modified by evolution to perform different functions, but they are all evolutionarily traceable to the fins of crossopterygian fishes, in which that basic arrangement of bones was first established. Analogous structures, by contrast, may resemble each other because they perform the same function, but they have different evolutionary origins and often a different structure, the wings of insects and of birds being a prime example of this.

What does similar bone structure mean?

Homologous structures are structures that are similar in related organisms because they were inherited from a common ancestor. These structures may or may not hav e the same function in the descendants. Figure below shows the hands of several different mammals. They all have the same basic pattern of bones.

What is it called when different species have similar bone structures?

These likenesses in structure, called homologies, are the result of descent from a common ancestor. In related species, the same anatomical features evolved into distinct forms as they were used in different environments or for different functions.

What does it suggest if organisms have the same anatomical structures?

Similar body parts may be homologous structures or analogous structures. Both provide evidence for evolution. Homologous structures are structures that are similar in related organisms because they were inherited from a common ancestor. These structures may or may not have the same function in the descendants.

Does the similarity in bone structure suggest a common ancestor?

ANALOGOUS STRUCTURES ARRANGED SIMILARLY YES IT SUGGESTS A COMMON ANCESTRY. THE SPECIES ILLUSTRATED HAVE SIMILAR BONE STRUCTURES SUGGESTING COMMON ANCESTRY. HOWEVER THOSE STRUCTURES HAVE DIFFERENT FUNCTIONS DEPENDING ON EACH SPECIES' ENVIRONMENT. THEY SHARE THE SAME FUNCTION.