Chinese researchers have uncovered how ancestors' experiences like trauma and stress are passed down through generations.

Researchers from Xiamen University conducted a meta-analysis of 139 experimental studies involving 112 plant and animal species to investigate transgenerational effects.

A meta-analysis is an examination of data from a number of independent studies on the same subject in order to determine overall trends.

According to the researchers, an adaptive transgenerational effect refers to ancestors' experience of stressful or favorable environments that can be beneficial to offspring.

They found that the strongest transgenerational effects are in annual plants and invertebrates, and the effects for their offspring are strong regardless of whether the experiences are stressful or benign.

For instance, when the previous generation experienced predation, the offspring would be more defensive against predation; when the previous generation grew up under weak light, the growth rate of their offspring would also increase under weak light.

Meanwhile, vertebrates like rodents and humans only responded to favorable environments and did not develop an adaptive transgenerational effect for stressful conditions. The researchers said this is probably because vertebrates can avoid stressful conditions through their mobility.

The findings have been published in the journal Ecological Letters. The researchers said the study provides insights into improving crop yields, making them better adapt to stressful environments like drought, warming and pests.