Genetic diversity, the variation in DNA blueprints within species, determines the success of captive breeding programs for animals like elephants and tigers in zoos. This variation influences form, chemistry, and behavior, all tied to an organism’s genetic code.
For most species, assessing genetic variation remains challenging, especially amid rising climate unpredictability. Understanding which genetic variants best withstand environmental shifts is vital, particularly for crops we rely on.
Lessons from Nature’s Lab
Human activities amplify unpredictable changes, though they occur naturally too. Rosemary and Peter Grant’s 40-year study of finches on Daphne Major in the Galápagos revealed how beak size differences, linked to genetics, dictated survival during El Niño rains favoring small beaks for soft seeds, or droughts benefiting larger beaks for tough seeds.
This demonstrates genetic diversity equips species to handle flux, akin to a multi-tool Swiss knife over a single-blade version—you can’t predict needs in advance. Visual inspection often fails; humans share 99.9% coding DNA despite vast cultural differences, due to our brief 300,000-year history versus millions for other mammals.
Measuring the Invisible
Tropical fruit flies show over 4% genetic variation and 13 clusters despite identical appearances, underscoring the need for DNA sequencing across populations. Only a fraction of species have been sequenced; museums and botanic gardens offer efficient solutions via their collections.
Conservation now prioritizes genetic alongside species preservation. Kew’s Millennium Seed Bank, holding 2.4 billion seeds from 40,000 species, shifts focus to capturing wide genetic representation per species for spacecraft-like safeguarding.
Beyond Species: Evolutionary Heritage
The thylacine’s extinction erased not just a species resembling dogs via convergent evolution—despite being a marsupial with pouches—but millions of years of unique evolutionary branch. Phylogenetic diversity, totaling tree branch lengths in time or DNA differences, quantifies such losses.
Evolution builds adaptations like birds’ light bones, carnivores’ teeth, or plants’ toxins and fire resistance through natural selection of beneficial mutations. This process yields life’s staggering variety, emphasizing why preserving genetic and evolutionary diversity matters profoundly.
Source : The Hidden Universe: Adventures in Biodiversity by Alexandre Antonelli
Goodreads : https://www.goodreads.com/book/show/56669607-the-hidden-universe
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Thinking Beyond Science 
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