life history
Quick Summary
A life history describes the changes an organism undergoes from its beginning to its natural death. It encompasses the sequence of events related to survival and reproduction. This includes factors like breeding frequency, age at first reproduction, number of offspring, and whether reproduction is sexual or asexual. These variations significantly impact an individual's reproductive success and the dynamics, ecology, and evolution of populations.12
Life history strategies can be broadly categorized into two types: r-selected and K-selected. r-selected species are opportunistic, reproducing early and having many offspring, often in variable environments. K-selected species reproduce later, have fewer offspring, and tend to remain near the environment's carrying capacity, typically in more stable environments.2
The timing and length of the reproductive phase are crucial. Natural selection generally favors shortening the generation interval and increasing offspring numbers. However, delaying reproduction can lead to more robust offspring, and restricting the reproductive period is essential for new generations to emerge and for evolutionary trial-and-error with new genetic combinations. Death is a necessary part of this process, allowing for evolutionary innovation.3
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