Question

Explain five pieces of evidence that supports the gradualistic mode of an evulotionary trend?

Answer 1

Ans- The gradualism model of evolution proposes defines the evolution of new species from a progenitor species that proceeds slowly but continuously. The fossils record, vestigial structures, homologous structure, comparative embryology and molecular studies are a piece of evidence that supports the gradualistic mode of an evolutionary trend.

1.Fossils records- Fossils records is a preservation process of ancestors that lived in past and show a smooth and gradual they change from one form of life to another.

2. Vestigial structures- The vestigial organ is homologous in structure and reduced in size which is inherited from a common ancestor and used to compare the original version of the structure. Therefore, it can be considered as an evidence for the evolutionary process. Examples of vestigial organs are Python hip bones and human tailbone.

3. Homologous structures- Homologous structures are similar in function that inherited from a common ancestor. They are found in different species such as the human arm, whale fin, batwing. It can help in studying how the bones of an animal are same in different species.

4.Comparative embryology- Comparative embryology is considered as evidence for the evolutionary process because during developmental process all the embryos are similar until they differentiate. Humans, dogs, snakes, fish, monkeys, eels all belong to phylum Chordata. Initially, all chordates have an embryo that resembles each other. All have gill slits, tails, and specific anatomical structures involving the spine. In humans and other non-fish, gill changed into the bones of the ear and jaw at a later stage in development. This evidence proves that all the members of phylum develop from a common ancestor.

5.Molecular evidence- By comparing the DNA and find the differences and similarities of DNA and other molecules we can find out the species which are more or less related.About 96% of human genes are common in chimpanzees that do not mean that humans are evolved from chimpanzees, but it can be considered that we shared a common ancestor in the past.