How 'Regulatory Evolution' and Gene Recycling Created the Bat Wing
UPSC Relevance
Prelims: General Science (Biology - Evolution, Genetics, Apoptosis, Transcription Factors); Science & Technology (Biotechnology - Transgenic animals, RNA sequencing).
Mains:
General Studies Paper 3 (S&T): Awareness in the fields of Bio-technology; Science and Technology- developments and their applications and effects in everyday life. This discovery is a classic example of a fundamental breakthrough in Evolutionary Developmental Biology (Evo-Devo).
Key Highlights from the News
A new study answers long-standing scientific questions about how bat wings, the only mammals capable of flight, evolved.
The old understanding was that bats completely prevent apoptosis (programmed cell death) to retain the skin between their fingers. The new study states this is not entirely correct.
Instead, evolution used a new strategy: "regulatory evolution" (evolution through regulating gene activity).
New Discovery:
Evolution repurposed a specific type of cell called fibroblasts, found in other parts of the body, to be present between the fingers.
Two important genes, MEIS2 and TBX3, which are normally inactive during embryonic development, were reactivated in bat wings.
When these two genes were artificially activated in mouse embryos, they developed webbed digits, similar to a duck's. This is significant evidence for the discovery.
This is an excellent example of evolution repurposing existing genetic mechanisms (evolutionary co-option or exaptation) for new needs.
This finding may also help in studying genetic conditions in humans, such as Syndactyly, where fingers are fused.
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