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Defending the Christian Worlview, Creationism, and Intelligent Design

This is my personal virtual library, where i collect information, which leads in my view to the Christian faith, creationism, and Intelligent Design as the best explanation of the origin of the physical Universe, life, and biodiversity


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Defending the Christian Worlview, Creationism, and Intelligent Design » Theory of evolution » Sperm and egg evolution

Sperm and egg evolution

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1Sperm and egg evolution Empty Sperm and egg evolution Sun Oct 11, 2020 3:17 pm

Otangelo


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Sperm and egg evolution

Sperm are the most diverse cell type despite their homologous function across taxa of securing male fertility 3

The sperm-production gene is apparently so critical to life that it hasn't changed since every animal's common evolutionary ancestor—likely just a blob of cells—arose some 600 million years ago, the researchers conclude. 2 The gene is found in a wide range of sexually reproducing creatures, including flies and humans.

Why do Fruit Flies  Have Giant Sperms?

Sperm and egg evolution IGLVRM5WOQH4EK4XVA6POYLZAM

When mating time rolls around, most male animals offer a glut of tiny sperm. Fruit flies operate a little differently. They deliver a few gigantic sperm. In fact, male Drosophila bifurca flies can produce sperm that are 5.8 centimeters long—20 times longer than their own bodies.

My comment: That means, if human sperms had the same size compared to average male height, a human sperm would be 36 meters long. ( A human sperm cell consists of a flat, disc-shaped head 5.1 µm by 3.1 µm and a tail 50 µm long  1×10−6 or 1meter has 1,000,000 )  That means, one meter contains 18.100 sperms.  That means, a sperm of Drosophila bifurca is proportionally 655 thousand times longer than human sperm. 

The size range alone is huge across the animal kingdom: the porcupine's 28-μm sperm contrasts dramatically with the current world record holder Drosophila bifurca, whose spermatozoal leviathans stretch to 6 cm. Maintaining the species-specific sperm size range seems to be vital: nutritional limitation that halves the resources available for males to invest in gametogenesis leads to a halving in the number of sperm produced but no reduction in the size of the sperm. Why this 2,000-fold variation in sperm size across species, when all have the same fundamental task?

These extravagant sperm are puzzling to scientists because flies have to invest a lot of energy into making them. Long sperm in males requires consequently long reproductive tract in females. 




1. https://www.popsci.com/how-fruit-flies-evolved-giant-sperm/
2. https://www.nationalgeographic.com/news/2010/7/100716-sperm-gene-600-million-years-evolution-male-pill-science/
3. https://royalsocietypublishing.org/doi/10.1098/rspb.2020.1286

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