Speciation: The Natural Formation of New Species
Speciation is a fundamental concept in evolutionary biology. It refers to the evolutionary process by which new biological species arise.
Understanding Speciation
The core idea behind speciation is the splitting of an existing species population into two or more distinct populations that are reproductively isolated from each other. This means they can no longer interbreed successfully.
Key Aspects of Speciation:
- Natural Process: Speciation occurs naturally over time due to various evolutionary mechanisms like genetic drift, mutation, and natural selection, often driven by geographic or reproductive isolation.
- Formation of New Species: It results in the emergence of new, distinct species from a common ancestral species.
- Reproductive Isolation: This is a crucial factor where populations diverge to a point where gene flow between them ceases.
Analysis of Options:
- Option 1 & 2 (Extinction): These options describe extinction, which is the opposite of speciation (species dying out, not forming).
- Option 4 (Characterisation): This involves identifying and describing species based on their traits, not the process of their formation.
- Option 3 (Splitting Naturally): This accurately describes speciation – one species dividing into two or more new species through natural evolutionary processes.
Therefore, the definition aligning with the biological process of speciation is the natural splitting of one species into two or more.
Important Questions from Evolutionary Mechanisms
The frequency of homozygotes in a diploid population is 0.68. Assuming that the population is in Hardy-Weinberg equilibrium, the frequencies of the two alleles are
Convergent evolution creates:
Given below are the possible reasons of high probability for extinction of species:
(i) Increased homozygosity of alleles
(ii) Increased heterozygosity of alleles
(iii) Decreasing population sizes
(iv) Increasing demographic stochasticity
(v) Decreasing environmental stochasticity
Which one of the following options represents the correct combination of reasons that can lead to the highest probability of extinction of species?
Given below are proposed analogous structures among organisms.
A. wings of birds and bats
B. wings of bats and tetrapod digits
C. tendrils of Vitis and tendrils of pumpkin
D. tubers of potatoes and sweet potatoes
E. fins of fish and flippers of a whale
Which one of the following options correctly states the analogous structures?
According to Hamilton's rule, 'r' is the coefficient of relatedness between two interacting individuals, 'B' is the benefit to thr recipient and 'C' is the cost to the donor. Which of the following relationships will result in an altruistic behaviour?
