Understanding Natural Selection Types
Natural selection is a core mechanism of evolution. It describes how organisms with traits better suited to their environment are more likely to survive and reproduce, passing those advantageous traits to their offspring. Phenotypes are the observable characteristics of these organisms.
Types of Natural Selection Affecting Phenotypes
Directional Selection
This type of selection favors individuals at one end of the phenotypic spectrum. Over time, the average phenotype of the population shifts in that direction.
Saltation
Saltation refers to a sudden, large evolutionary leap or mutation, rather than a gradual process driven by selection acting on existing variation. It is not a type of natural selection in the context of determining peak phenotypes.
Disruptive Selection
Disruptive selection favors individuals at both extremes of the phenotypic range over those with intermediate phenotypes. This can lead to a population with two distinct phenotypic groups.
Stabilising Selection
Stabilising selection occurs when individuals with intermediate phenotypes are favored over those with extreme phenotypes. This reduces phenotypic variation within the population. Consequently, the average phenotype becomes more common and pronounced, effectively causing the phenotypes to 'attain a peak' around the mean.
Conclusion
Based on the definitions, Stabilising selection is the mode where the most common or average phenotypes are favored, leading them to become more prevalent and reach a peak in the population's distribution.
Similar Questions
- In which phase of meiosis, the homologous chromosome separate while sister chromatids remain associated at their centromeres ?
- Specialized internal membrane of chloroplast responsible for light reaction.
- Choose the gaseous harmone among the following :
- An example for non photosynthetic organ of the plant :
- A microscope that uses visible light to observe specimens :
- Choose the basic dye among the following :
- A most widely employed microscopic staining method in bacteriology :
- Under mechanism of evolution, the work by Hugo deVries reported large difference arising suddenly in a population of which plant.
- Choose the extinct vertebrate among the following :
- The revolution in horticulture to promote the production and productivity of horticultural crops.
Important Questions from Miscellaneous
- Which of the following relationships is/are not true?
(A). Most probable velocity = $\sqrt{\frac{2RT}{M}}$
(B). PV = $\frac{3}{2}kT$
(C). Compressibility factor Z = $\frac{pV}{nRT}$
(D). Average kinetic energy of gas = $\frac{1}{2}kT$
Choose the correct answer from the options given below - Match List-I with List-II
List-I List-II Electronic Configuration First Ionisation energy (kJ mol$^{-1}$) (A). ns$^2$ (I). 2100 (B). ns$^2$np$^1$ (II). 1400 (C). ns$^2$np$^3$ (III). 800 (D). ns$^2$np$^6$ (IV). 900
Choose the correct answer from the options given below: - The shielding constant of a 2p electron (calculated using Slater's rules) is
- Match List-I with List-II
List-I List-II Spectroscopy Property (A). Raman (I). Polarizability (B). FTIR (II). Dipole Moment (C). UV-Visible (III). Absorbance (D). NMR (IV). Spin
Choose the correct answer from the options given below: - The structure of protein comprises of:
(A). Primary structure of protein is associated with amino acids
(B). Secondary structure of protein is associated to peptides
(C). Tertiary structure of protein is associated with polypeptide chains
(D). Quaternary structure of protein is associated with polypeptide chains
Choose the correct answer from the options given below:
