The recent findings published in the journal ‘Scientific Reports’ have brought forward new insights about the African Baobab tree, revealing that it has 168 chromosomes, contrary to previous studies estimating between 96 and 166. This study represents a significant step in enhancing our understanding of this ancient tree, and is expected to be valuable for future genetic conservation efforts.
Understanding Baobabs
Baobabs are deciduous trees that can reach heights between 5 and 20 meters. The term ‘deciduous’ pertains to trees that shed their leaves during specific seasons and is characterized by the dominance of broad-leaved tree species. A prime example among the nine baobab species is the African baobab (Adansonia digitata), which is endemic to mainland Africa and commonly spotted in the African Savannah. This ecosystem is a tropical grassland with warm temperatures all year round, receiving most rainfall during summers. It features grasses and sparse or small trees which do not form a closed canopy, hence permitting sunlight to hit the ground directly.
The African Baobab: An Ancient Lifeline
With the help of Carbon-14 dating, scientists have found an African baobab specimen in Namibia that’s approximately 1,275 years old, making it one of the oldest known angiosperm trees. Being a succulent, the African baobab absorbs and stores water in its trunk during the rainy season, which enables it to yield nutrient-dense fruit in the arid dry season. These trees can survive for over a thousand years and act as a source of food, livestock fodder, medicinal compounds, and raw materials. However, since 2005, several of the oldest and largest baobabs have died or lost their oldest stems, possibly due to climate change impacts.
Angiosperms and Gymnosperms
Angiosperms, where the mature seed is encased by the ovule (like an apple), are also known as hardwoods. They typically have broad leaves that change color and die every autumn, with examples including oaks, maples, and dogwoods. However, several angiosperms, like rhododendrons, live oak, and sweetbay magnolia, retain their leaves throughout the year.
In contrast, gymnosperms are plants whose seeds are not enclosed in an ovule, much like a pine cone. Often referred to as softwoods, gymnosperms usually possess needles that stay green all year round. Pine, cedar, spruce, and fir trees exemplify this type. Nevertheless, certain gymnosperms such as ginkgo, dawn redwood, and bald cypress do drop their leaves.
Carbon-14 Dating: A Tool for Age Determination
Often referred to as radiocarbon dating, Carbon-14 dating is a method of determining age that relies on the decay of radiocarbon (Carbon-14) into nitrogen. Carbon-14 is constantly formed in nature through the interaction of neutrons with nitrogen-14 present in the Earth’s atmosphere. The necessary neutrons for this reaction are produced by cosmic rays interacting with the atmosphere.