This thesis studies the complexity of fundamental problems in dynamic, i.e., time-variant, ad-hoc networks. Based on the model by Kuhn et al. (Symposium on Theory of Computing 2010), the network is controlled by an adaptive adversary that tries to prevent the efficient execution of algorithms and only guarantees connectivity in each round. In this thesis, three main aspects are considered, which can be found in three different parts of the thesis. In the first part, the adversary is restricted geometrically and an information dissemination problem is analyzed. The second part focusses on the counting problem (How many nodes are there in the network?) and establishes a relation to information dissemination problems. Finally, the third part studies the continuous, i.e., the repeated, computation of aggregation functions (e.g., the maximum of all inputs given to all nodes) in more stable variants of dynamic networks.