Babies look perplexed and sound squealy all the time.
Youngsters are brimming with manic energy.
Biologists consider extinctions to be due to failure to adapt to environmental changes, and the “environment” includes other organisms. Exactly how species go extinct is still poorly understood, but the idea that the battle for survival is a common understanding among biologists, and ecosystems . makes the relationship explicit. There are many interacting variables, including those environmental nutrients, both inorganic and those provided by life forms. The ability of an organism or species to adapt is partly dependent on how specialized it is and how unique its habitat is. Absolute numbers, geographic distribution, position in the food chain (higher in the food chain is riskier), mobility, and reproductive rates all impact extinction risk. During the , about 80% of all animals were immobile. Today, 80% of all animals are mobile. The immobile animals were at higher extinction risk, for obvious reasons.
That baby fat look will have all but disappeared.
The evolutionary game for a species is for enough of its members to survive long enough to produce viable offspring. Organisms have adopted myriad survival and reproduction strategies, with astonishing diversity. There are many ways to win or lose that game, but every species eventually loses. More than 99.9% of all species that have ever lived on Earth became extinct. A mammalian species has a life expectancy of around a million years, while a marine invertebrate species has one of about . Today’s global extinction rate is more than 100 times the “normal” rate (“background rate”), and perhaps far greater, such as 10,000 times, due to human domination of the ecosphere. The current rates could rival and equal the rates during the greatest mass extinction of all: the .