More Harmful Effects of Smoking Weed While Breastfeeding. More medical studies need to be done to determine marijuanaâs effects on breast milk, but below are some of the areas studies have indicated contain risk factors.urthermore, marijuana use can diminish the abilities of a mother to take care of her newborn. The American Academy of Pediatrics advises nursing mothers not to use marijuana while breastfeeding. However, in some states medical marijuana is used to treat anxiety and other medical conditions.
We can see fossils of many other reptiles in rock of the same age and even older, but Archaeopteryx lithographica is the oldest known fossil to have feathers. We conclude that this animal is a link between reptiles and birds and that birds are descended from reptiles.ossils can be used to recognize rocks of the same or different ages. The fossils in this figure are the remains of microscopic algae. The pictures shown were made with a scanning electron microscope and have been magnified about 250 times.
Chemical fossils are chemicals found in rocks and fossil fuels (petroleum, coal, and natural gas) that provide an organic signature for ancient life. Molecular fossils and isotope ratios represent two types of chemical fossils.ossils may also consist of the marks left behind by the organism while it was alive, such as animal tracks or feces (coprolites). These types of fossil are called trace fossils (or ichnofossils), as opposed to body fossils.