Question

In plant communities today, leaf morphology is correlated with mean annual temperature, so paleobotanists use fossil leaf morphology to estimate the mean annual temperature of paleoclimates. However, the angiosperm fossil record contains an overabundance of samples fossilized near lakes or rivers where vines are especially common. Since vine leaves have a somewhat different association with temperature, use of data from vine-rich locations leads to mean average temperature estimates that are lower than actual recorded temperatures in modern plant communities. This potential bias in paleobotanical climate estimates is due to which type of bias in the fossil record? (R. J. Burnham, N. C. A. Pitman, K. R. Johnson, and P. Wilf. 2001. Habitat-related error in estimating temperature from leaf margins in a humid tropical forest. American Journal of Botany 88:10961102.)

Answer 1

Habitat bias (the conditions where organisms live have different potential to produce fossils)

Preservational bias (Some environments offer better conditions to produce fossils than others; transitional environments like deltas and shores can also accumulate organisms dragged from neighbouring environments)

Step-by-step explanation:

Depositional environments are those with a rich influx of sediment and a low erosion rate. Fossils are more likely to be formed in these types of environment, such as river and lakes. According to Burnham et al. 2001, samples from closed canopy forests are better predictors of temperature than open canopy areas. Lakes and rivers are considered open canopy areas. On top of that, because of the depositional nature of these areas, they can reflect a mixture of plant fossils from all the surrounding areas, thus relying on the most abundant fossil leaves could increase the noise in the estimated temperature. A solution for this is to rely on the leaves from woody plants, more likely to be from closed canopy areas, even if they are less abundant in the sample than lianas and vines.