Histone proteins aid in the compaction of DNA in cells and their modification can regulate gene expression. This second essay in a series on Epigenetic Mechanisms delves into how acetylation and methylation of histone proteins, as well as their repositioning along the DNA sequence, can cause this altered gene expression, with a continued discussion of the theme of epigenetic crosstalk which pervades this series.

Epigenetics is the study of the modifications applied to DNA which change how that DNA is used. In this essay series, the epigenetic mechanisms of DNA methylation, histone modification, and non-coding RNA will be discussed with a particular focus on how the epigenetic marks work together to enact important developmental events such as X-chromosome inactivation. This first essay focuses on DNA methylation, specifically the addition, removal, and interpretation of the methyl mark, how DNA methylation is localised in the genome and how that location can change the effect DNA methylation.

Mycorrhizal Symbiosis is a mutually beneficial relationship in which plants are connected to fungi in order to exchange nutrients and more, hence enhancing the survival of everybody involved. This essay discusses the two main types of mycorrhizal symbiosis, arbuscular mycorrhizal and ectomycorrhizal symbiosis, before focusing on common mycorrhizal networks, also known as the ‘Wood Wide Web’, a communication network that provides a wide range of benefits for the plants, fungi, and ecosystem as a whole.

Colonisation of animals by parasites and debris is common and potentially harmful. That is where cleaners come in. These small individuals form symbiotic relationships with their clients, receiving food while their clients receive increased survival. In this essay I discuss three examples of cleaning symbioses – the aquatic cleaning gobies and fish, and branchiobdellids and crayfish, as well as the terrestrial oxpecker and mammals – and how the survival of the individual is secured when individuals work together.

The Western honeybee is a eusocial species of bee that lives in colonies of several thousand and pollinates many species of plant that humanity relies on for both food and manufacturing. This essay takes the reader through a year in a honeybee colony, from nectar collecting and hive maintenance in summer, to survival activities in autumn and winter, to brood rearing and colony swarming in spring.

As humans, we commonly believe that our ability to communicate with each other sets us apart from other animals. In this essay, I discuss examples of communication in prairies dogs, baboons, moths, domestic dogs, and dolphins to dispute this belief. I also describe the four main four of communication – acoustic, visual, chemical, and tactile – and how all four are used in various contexts throughout the animal kingdom.

As dreams have been a universal aspect of the human experience for thousands of years it is unsurprising that they have garnered much attention from scientists who have attempted to explain why they exist. This essay discusses just some of the theories for the biological mechanisms – the Activation-Synthesis/AIM and Neurocognitive models – and the function – the Psychoanalytic, Memory Consolidation, Simulation, and Problem-Solving theories – of dreaming.

14 000 years ago, the last Ice Age ended, and trees began to colonise the UK and form dense woodland. Since then, there has been a great amount of change in the composition, coverage, and overall health of our country’s woodlands. This essay briefly describes the ways in which the woodlands themselves have changed and how people have interacted with the woodlands over the millennia, from Stone Age sustainability to Roman ownership, and Medieval stability to Modern destruction.

In this final essay in my series on de-extinction, I set out 15 questions surrounding justification, feasibility, likelihood of success and negative impacts, and public acceptance that can be used to assess the suitability of a de-extinction candidate species. I then use these criteria to evaluate the woolly mammoth, passenger pigeon, thylacine, dodo, and aurochs.

De-extinction is a complicated and divisive topic with potential benefits and drawbacks and a great amount of uncertainty. This essay takes a holistic look at the de-extinction debate, discussing the ways in which de-extinction could help our planet and the species that live here as well as the various risks involved in practicing the discipline. Due to the relatively theoretical nature of current de-extinction literature, this essay emphasises the uncertainty in evaluating the benefits and risks of any one de-extinction project.

De-extinction is the science of resurrecting extinct species, or their characteristics, through backbreeding, cloning or genetic engineering. This essay, the first in a three-part series, discusses these three techniques, the advantages and disadvantages of each, and how they have been applied to the field of de-extinction.